Photochromoscopic apparatus.



Patented Oct. 23, i900.

F. E. IVES.

PHOTCHBMOSCPIC APPARATUS.

3 Sheets-Sheet 2.

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Patented Oct. 23, |900.

F. E. IVES.

PHOTOCHROMOSCOPIC APPARATUS.

vhpphcrminn led Max. 9, 1900- No Modem 3 Sheets-Sheet 3.

UNITED STATES PATENT OFFICE..

FREDERIC EUGENE IVES, OE PHILADELPHIA, PENNSYLVANIA.

PHOTOCHROMOSCOPIC APPARATUS.

SPECIFICATION forming part of Letters Patent No. 660,442, dated October23, 1900.

Application filed March 9, 1900l -ierial No. 8.093. (No model.)

To LZZ wil/0m, t may concern:

Beit known thatI, FREDERIC EUGENE lvEs, a citizen of the United States,residing in Philadelphia, Pennsylvania, have invented certainImprovements in Photochromoscopic Apparatus, of which the following is aspecification.

The object of my invention is to provide in photochromosoopic apparatussimple means for equalizing the size of the three images produced from asingle view-point and disposed side by side in the same plane or for theoptical superposition at a singl'e viewpoint of three such images, anobject which I attain in the manner hereinafter set forth, referencebeing had to the accompanying drawings, in which- Figure l is asectional plan view of a photochromoscopic camera constructed inaccordanceVV with my invention. Fig. 2 is a view illustrating anotherform of camera embodying the invention. Fig. 3 is a viewillustratingstill another form in which the invention can be embodied, and Figs. 4,5, 6, 7, and 8 are sectional views showing other modifications of theinvention.

What l term a photochromoscopic camera is an instrument for producingfrom a single view-point three images side by side in the same plane,and a photochromoscope is an instrument for viewing from a singleview-point three such images. When such apparatus is so constructed thatthe distance from the view-point to the outer imagesis greater than thedistance from the view-point to the central image, it becomes necessaryto provide an optical compensation for this difference in distance inorder to equalize the images. In the instrument shown in my PatentNo.546,889, dated September 24, 1895, this was accomplished by introducingadditional reflecting-surfaces, by which the llength of the ray betweenthe central image and the viewpoint was made equal to that of thecorresponding rays between the view-point and the outer images. In mypresent invention the cone of rays to each outer image is stretched outandthe focal pointiextended by introducing in the path of these rays a`body of glass or other refr-acting medium, which in technical languageretards the light-ray.

In Fig. l the casing or box of the camera is represented at l, while 2and 3` are transparent inclined reflectors located in the pat-h of theincident ray, the rays reflected from the plate 2 being directed onto aninclined opaque reilector4 and the rays reected from the plate 3 beingdirected onto an inclined opaque reflector 5, so that all three seriesof rays will be directed rearwardly through suitable lens constructions6 and will form images side by side upon a single plate contained in aplate-holder 7 at the rear end of the box, the rays before reaching theplate passingr through suitable color-screens 8. The reflected rays,which form the side images of the series, also pass through rectangularblocks 9 of glass interposed in the path of the rays, between the lensstructure 6 and the plate', whereby the focal point of these side raysis extended to`such an extent that the images formed upon the sensitiveplate will all be equal and properly focused. For instance, if the axialrays to the outer images are two inches longer from the view-point thanthe axial ray to the central image it is necessary to extend the focalpoint of the outer rays to the extent of two inches, and this may beaccomplished by introducing in the path of each longer ray six inches oftransparent substance having a refractive index of 1.5,which isapproximately the refractive index of crown-glass. If a heavy silicateflint glass having a refractive index of 1.96 is used, a length ofslightly more than four inches will be suflcient, or in place of ,asolid block of refractive medium a glass tank of proper size and shapefilled with a suitable liquid may be I employed-as shown, for instance,at 9a in Fig. 5.

In the construction shown in Fig. 2 a single lons ta is employed at thefront of the camera instead of the series of lenses within the camera,as shown in Fig. l, and one of the coincident, though in reality veryslightl separated. Both refracting-blocks in this case lOO It will beevident that in carrying out my invention two or more blocks of glasscemented together may be used in piace of a single block. Thus in Fig. 5I have shown four blocks 9b used in this way, or the blocks may beseparated from each other-as shown, for instance, at 9c in Fig. 6-or oneor more rectangular blocks may be combined with a prism, or said prismmay be combined with one or more tanks or cells filled with liquid. Thusiu Fig. 7 I have shown a prism 9(l oombined With three rectangularblocks 9e, and in Fig. S I have shown said prism 9d combined with arectangular vessel 9a, filled with liquid.

Having thus described my invention, I claim and desire to secure byLetters Patentv l. In photochromoscopic apparatus, the combination ofmeans for dividing the rays from the view-point or collecting thedivided 1a5s at the view-point, with transparent bodsaid transparentrefractive bodies having portions which also serve as redectors,substantially as specified.

In testimony whereof I have signed my name to this speciiication in thepresence of two subscribing witnesses.

FREDERIC EUG ENE IVES.

Witnesses:

JOHN W. TAeGART, F. E. BEoHToLD.

